Qwen3.8 27B

User compares Qwen3.8-27B Q4_K_M on an Intel Arc Pro B60 24GB under WSL2 with Mesa Dozen against the native Windows Vulkan build of llama.cpp b11889. Native Windows gives 339.4 t/s prompt and 15.6 t/s generation with -ngl 99; the WSL2 run segfaults during generation after 49.9 t/s prompt. The crash is in libLLVM-14.so from Intel's Windows driver package, at the same offset across four crashes, two quants and both llama-bench and llama-cli. It runs at -ngl 0 or 1 and crashes from -ngl 2 up, with 23.6 GiB VRAM free. Other models on the same card are 8 to 40 times slower under WSL2: Ornith 1.5 9B Q8_0 at 141.7 / 4.1 versus 975.8 / 36.2, and Qwen3-Coder-30B-A3B Q4_K_M at 34 / 2.5 versus 788.8 / 99.2. Dozen reports matrix cores none and a non-conformant Vulkan warning, while native Windows reports KHR_coopmat.